Thomas j



Patented Nov. 29, 1898. T. J. MURPHY.

JUNCTION BOX.

(Application led Apr. 22, 1895. Renewed Dec. 31, 1897.-)

(No Model.)

jizz/mfom Wg M@ we: mams PEYSRS oo, PHoramNo. wAsmscmN n c UNITED STATESPATENT OFFICE.

THOMAS J. MURPHY, OF NEIV YORK, N. Y.

JUNCTION-BOX.

SPECIFICATION forming part of Letters Patent No. 614,882, dated November29, 1898.

Application i'iled April 22, 1895. Renewed December 31, 1897. Serial No.665,255. (N0 modem vTo all whom it' may concern:

Be it known that I, THOMAS J. MURPHY, a citizen of the United States,residing at New York city, 'in the county and State of New York, haveinvented a certain new and useful Improvement in Junction-Boxes, ofwhich the following is a specification.

I-Ieretofore j unction-boxes have been made which from their mode ofconstruction were not secure against iire risks and which were expensivein construction.

The object of my invention is the production of a cheap and simple junction-box which is especially adapted for use in connection withsystems of electrical conduiting for interiors and which will be safefrom ire risks occurring within lthe box as well as from leakages ofcurrent.

In the accompanying drawings, forming part of this specification, Figurel is a plan view of a junction-box embodying my invention with the coverremoved. Fig. 2 is a cross-section thereof on the line 2 2 of Fig. lwith certain of the parts removed. Fig. 3 is a longitudinal sectiontaken on the line 3 3, Fig. 1. Fig. 4 is a detail of a nipple to whichthe conduits are attached. Fig. 5 is a modified form of box. Fig. 6 is alongitudinal section thereof through the line 6 6, Fig. Fig. 7 isanother form of box. Fig. Sis a longitudinal section thereof on the lineS S, Fig. 7. Fig. 9 shows afbox with the cover in place and withoutnipples, and Fig. 10 is a cross-section thereof on the line 10 lO.

A is thewooden casing of the box, which serves to receive the lining B.This lining is of a refractory non-conducting material and to its usethe box owes its chief advantages. I prefer slate, as at once fulfillingthe objects named and at the same time being cheap. As shown in thesection Figs. 2 and 3, the bottom of the box, as well as the sidesthereof, is lined with this refractory non conducting material. A coveralso lined with the same material is to be used with this box,

so that the whole interior of the box is made thereof. In Figs. 5, 6, 7,8, 9, and 10 I have shown this simple form of slate-lined box. In thosefigures, C represents -the seat for the door, which is formed by the topedge of the slate lining of the box.

In Figs. 1, 2, and 3 is shown what I call my double slate-lined box-thatis to say, I take the box already described and within it form anotherbox` D of the same refractory and insulating material-as, for instance,slate, as shown-by preferably providing a bed-block of slate F.,surrounded by the four walls, (lettered D,) as shown in Figs. 1 and 3particularly. This double slate-lined box is particularly advantageousfor the room it affords within which to make the distribution of theconductors. The electrical bindingposts, safety-fuses, or otherelectrical appliances used in boxes of this nature are mounted upon theslate base E, as shown, or in any suitable manner.

In order to tit the box for use with the tubes used in electricalinterior conduiting, I provide a short piece of pipe F, threaded, asshown, and pass it through the wooden frame A, which frame iscountersunk on the side next the slate lining, and place a Washer G onthe threaded pipe within the recess. The outer end of the short sectionof screwthreaded pipe receives another washer II, as shown moreparticularly in Fig. 4, these washers serving to keep the pipe in place.It is obvious that a threaded conduit-pipe might be secured directly tothe projecting nipple or a suitable protecting-coupling used to securethe said pipe to the nipple. By this arrangement instead of passing theconduitpipe directly into the interior of the box, where it might bedifficult to make the connection, the connection is made on the outside,where there is usually ample room to work. Again, by this arrangement Iavoid weakening the slate lining to a great extent, fory the reason thatI do not need to bore the same to the extent of the full outsidediameter of the conduit-tube, for by the arrangement shown the nipple Fprojects against the slate lining, and it is necessary only to providean opening in the slate lining large enough to take therethrough theconductors I, which opening of course is only about as large as theinterior diameter of the nipple.

It will be observed that when a box is completely lined with slate orother refractory non-conducting material in the manner I have describedthere will be absolutely no danger of leakages of current therefrom, andshould there be any crosses, blowing of safety-fuses,

IOO

or short-circuits within the boX any aroing resulting therefrom will beeonnecl to the interior of the box and will not set lire to surroundinginflammable materials, nor will the box be heated up by low-resistancecrosses of long duration, as would a metal box Without a similar lininO.

I claim- A box for mounting and Connecting eleotrieal Conductors,comprising an exterior Wooden shell, a lining of a refractory,nonoonduoting material therefor, a cover provided with a similar lining,and a screw nipple or nipples extending through said eXterior Woodenshell against the lining, said lining being oountersun k and receiving1a Washer, with a Washer on the outside of the Wooden shell, allsubstantially as set forth.

This speoication signed and witnessed this 20th day of April, 1805.

THOMAS J. MURPHY. Witnesses:

JOHN R. TAYLOR, S. O. EDMoNDs.'

